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How to write this equation using PDE in COMSOL
I find that I can't write this equation into COMSOL using PDE module. J+u*J×B=-σ*▽Φ, J and B are both vectors. I have attached a picture of this equation.Thank you very much.
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heating a block of material by a moving laser
Hello everyone, I'm a beginner at COMSOL, so probably my question is quite stupid to the frequent users of COMSOL. I want to simulate a laser hardening process. At this time only the temperature field...
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Fluid flow
Hi, I am trying to do fluid flow simulation of a peristaltic pump by following COMSOL model example(www.comsol.com/model/download/...odels.sme.peristaltic_pump.pdf).But when I set fluid flow global...
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Material colors
Hi, how do can we add colors to materials? I would like the copper to be brown, epoxy green and so on. It makes things much easier to understand that I assigned the correct materials to each domain....
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move an entire array without having to select each sub-component
Hi, How can I move an array without having to select each of its object by hand (see screenshot for explanation)? In general when doing transforms is it not possible to manually enter the name of the...
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custom colortables
Dear all, do you know, whether it is possible to import custom colortables to Comsol? I am using Matlab (2013b) together with Comsol (4.4) and would like to produce a surface plot of my data that does...
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Membrane modelling
HI I am trying to model the effect of an external electrical field on a cell membrane. I believe that the most suitable boundary condition of the cell domain (cell-electrolyte interface) is the contact...
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PDE solver with variables at different points
Dear All, I am trying to solve a PDE where two terms contain variables at different points, something such as: u"(x) + u'(L-x)=f(x) This is a sample though, maybe there is no solution to this, but my...
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Two simultaneous COMSOL instances on one machine can save time
Dear community, today I tested something I had in mind for quite some time. On my workhorse computer, a 3.6 GHz Core i7 with 4 cores I always observe that a COMSOL calculation brings up CPU use to a...
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constraining dependent variable
Good day: I am trying to find the most effective method of implementing a constraint on a dependent variable. I am solving a classical diffusion equation (using Equation based modeling)of concentration...
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Initial conditions (steady state) to time dependent model
Hello All, I have a model where I want to find the steady-state solution to a time dependent model, I let it run with a large time block. Now I want to use this as the initial condition to the next...
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converting a general form of PDE to weak form PDE
Hi all , I am going to define a weak form of PDE on boundaries of a cylinder based on 4 dependent variables V_m, m, n , h. The following equations need to be converted to weak form but I do not know...
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How to best use Views in COMSOL?
The "Views" feature has been bugging me because I feel like I must not be utilizing it correctly. One thing I'd often like to do is save and lock a particular view in which a select group of domains...
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Phase Change
Hi all! I want to modeling of phase change in cryogen zone. And i have the problem. 1. What is the parameter "Ratio of specific heats" 2. Transition interval between Phase1 and Phase 2 - how much...
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Elastic strain energy
Is there a way to output the elastic strain energy (and not its density at certain points), as a number for my whole structure? i.e. the half of the volume integral of (stress x strain)? Thank you
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Power output magnet and coil generator
Hello, I would like to get the power output from my magnet and coil generator. I used this model: Voltage Induced in a Coil by Moving Magnet. Model ID: 14163 Of course the ’’open’’ voltage is known....
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increasing the speed of computation or parallel processing
Hi comsolers, Is there any way to increase the speed of computation for comsol? now, my time series is for one month with daily resolution. and it takes at least 4 or 5 hours to compute. and I have...
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Does Somebody have experience in PML for Electromagnetic?
Hi, Please let me know if you guys already worked with PML in RF module. I am doing a very simple structure but I can not implement PML for a long time. Thanks, Mohammad
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Reflecting and absorbing boundaries
Hi, I am new to Comsol. I would like to model some instantly released molecules inside a reservoir. The diffusion coff of these molecules is 6e-7 cm2/s. I have some questions about it. 1. How can i...
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point evaluation
Hi , How is it possible to know value of special location in the surface that has not been defined as a point? For example I want to know the value of Hydaulic head in a cross section fo soil column...
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